The present invention relates to compounds useful in the preparation of epoxy resins, and in particular to methods for preparing said compounds.
Epoxy resins are generally prepared by the reaction of epichlorohydrin with active hydrogen-bearing compounds, such as bisphenol A. Other methods for their preparation are the addition of glycidol to an acid chloride in the presence of triethylamine and Darzen's glycidic ester synthesis. More recently, epoxy acetal compounds with aliphatic main chains, have been prepared by reacting an unsaturated starting material with peracetic acid as described in U.S. Pat. No. 3,086,025, which is incorporated herein by reference. Unfortunately, the starting material is relatively expensive, thereby limiting the commercial application of the process.
Epoxy resins have been prepared from glycidyl ethers of cyclic ether anhydro hexitols as starting material via the epichlorohydrin process as is described in U.S. Pat. No. 3,041,300. However, these latter common epoxy components contain ether oxygen linkages in the backbone of the compound which are susceptible to oxidation and therefore provide poor weathering characteristics.
Accordingly, it would be highly desirable to provide a process for preparing an epoxy compound using an inexpensive and industrially available renewable resource which epoxy compound can be employed in order to provide an epoxy resin having good weathering characteristics.